Various User Defined Protocols (UDP) enable the transport of layer-2 datagrams, primarily but not limited to carrying media streams across packet switched networks. Prior art is limited to packet recovery, re-request mechanisms, and buffering; to management of the number of re-requests; or to dynamically adjusting the size of the buffer, the latter method having been developed specifically for voice communications. These mechanisms correct for packet loss due to congestion, router queue overflow or other transmission errors sometimes present when sending large bursts of data. Prior art lacks means to restore the original instantaneous bitrate and inter-packet spacing which are lost when buffering.
Failure to restore the original instantaneous bitrate and inter-packet spacing may lead to increased jitter, the irregular movement, variation, or unsteadiness that is perceived when watching, measuring or listening to such a media or data stream. All means cited in the prior art attempt to ensure the datagrams are as complete as possible, subject to an upper limit of the maximum time period that a buffer may hold. They do not attempt to restore the original instantaneous bitrate and inter-packet spacing. Prior art notes that transmission re-requests may in fact add jitter, and attempts to minimize the perception of it by time-stamping, leaving it to the receiver to make adjustments.